[morgal48]

Originally Posted by blue62

First thing.
Using a MAF sensors other than Bosch in these cars doesn't seem to work well.
Also make sure you get the proper replacement part number.

From your post I see this is a 2000S
Same thing I have in Guards Red.

When you unplug the MAF sensor the ECU reverts to a fixed fueling map.
The cold start or open loop map I believe. So the car should run sort of ok with the MAF sensor unplugged if all other things are ok.

So simplest things first.
Make sure your battery is in good shape. sounds silly I know.
A marginal battery can cause problems in these cars.

Make sure your plugs and coil packs are in good shape.
Marginal plugs or cracked coil packs can cause miss fires.

Make sure you don't have any exhaust leaks.
Exhaust leaks ahead of pre or post Cat O2 sensors cause false O2 sensor readings.

Make sure you don't have any vacuum leaks.
Vacuum leaks occur after the MAF sensor so that is unmetered air so vacuum leaks screw things up
I reread your post and see that you did a smoke test.

You may want to do a fuel pressure test at the fuel rail. Fairly simple to do.
Stalling can be a sign of low fuel pressure.



Couple of questions:
Is the car drivable with the MAF unplugged or does it still stall out?
Why did you replace the post Cat O2 Sensors?

Let us know how you go.

Battery is less than a year old - 13.76 V output.
Plugs and coil packs were replaced 23k miles ago. No misfires.
New O2 sensors cause that was all I could come up with after replacing the MAF (about 2500 miles on the new Bremi).
Still on jack stands - I flushed the brakes as well. I'll have it down today to see how it drives MAF-less.
Lastly, the double row IMS was installed 20k mi. ago. Original looks like new. Just wanted that off the table. :-]

Does the ECU reset every time I change the parameters by removing/replacing the MAF? If that is the case, does it "see" the settings from no MAF, then compensate when I start the engine with the MAF installed, going lean to rich, and essentially flooding the engine? Or does it move the opposite way and starve the engine of fuel? Or neither? IIRC the O2 sensors do not affect things until they reach temperature, relying solely on the MAF.